Consolidate DiagnosticHelper consumer setup

With frontend parseable-output removed, `DiagnosticHelper::initDiagnosticConsumers()` depends only on the parsed `CompilerInvocation` and can be invoked once, at the same site that constructs the helper. Move the `libSwiftScan` replay caller to call it immediately after `DiagnosticHelper::create()`, drop the call from `replayCachedCompilerOutputsImpl`, and remove the now-unused `DiagnosticHelper` parameter from both `replayCachedCompilerOutputsImpl` and the public `replayCachedCompilerOutputsForInput`.

Author: artemcm

include/swift/Frontend/CachingUtils.h

@@ -29,8 +29,6 @@
 
 namespace swift {
 
-class DiagnosticHelper;
-
 /// Create a swift caching output backend that stores the output from
 /// compiler into a CAS.
 llvm::IntrusiveRefCntPtr<cas::SwiftCASOutputBackend>
@@ -59,7 +57,6 @@ bool replayCachedCompilerOutputsForInput(llvm::cas::ObjectStore &CAS,
                                          const InputFile &Input,
                                          unsigned InputIndex,
                                          DiagnosticEngine &Diag,
-                                         DiagnosticHelper &DiagHelper,
                                          llvm::vfs::OutputBackend &OutBackend,
                                          const FrontendOptions &Opts,
                                          CachingDiagnosticsProcessor &CDP,

lib/Frontend/CachingUtils.cpp

@@ -22,7 +22,6 @@
 #include "swift/Frontend/CASOutputBackends.h"
 #include "swift/Frontend/CompileJobCacheKey.h"
 #include "swift/Frontend/CompileJobCacheResult.h"
-#include "swift/Frontend/DiagnosticHelper.h"
 #include "swift/Frontend/FrontendOptions.h"
 #include "swift/Frontend/MakeStyleDependencies.h"
 #include "swift/Option/Options.h"
@@ -164,7 +163,7 @@ static llvm::vfs::OutputConfig getOutputConfig(file_types::ID Type) {
 static bool replayCachedCompilerOutputsImpl(
     ArrayRef<CacheInputEntry> Inputs, ObjectStore &CAS, DiagnosticEngine &Diag,
     const FrontendOptions &Opts, CachingDiagnosticsProcessor &CDP,
-    DiagnosticHelper *DiagHelper, OutputBackend &Backend, bool CacheRemarks,
+    OutputBackend &Backend, bool CacheRemarks,
     bool UseCASBackend, bool WriteOutputHashXAttr) {
   bool CanReplayAllOutput = true;
   struct OutputEntry {
@@ -284,9 +283,6 @@ static bool replayCachedCompilerOutputsImpl(
   // Replay Diagnostics first so the output failures comes after.
   // Also if the diagnostics replay failed, proceed to re-compile.
   if (DiagnosticsOutput) {
-    // Only set up the diagnostic consumers if there are diagnostics to replay.
-    if (DiagHelper)
-      DiagHelper->initDiagnosticConsumers();
     if (auto E =
             CDP.replayCachedDiagnostics(DiagnosticsOutput->Proxy.getData())) {
       Diag.diagnose(SourceLoc(), diag::error_replay_cached_diag,
@@ -408,21 +404,20 @@ bool replayCachedCompilerOutputs(
 
   // Use on disk output backend directly here to write to disk.
   llvm::vfs::OnDiskOutputBackend Backend;
-  return replayCachedCompilerOutputsImpl(Inputs, CAS, Diag, Opts, CDP,
-                                         /*DiagHelper=*/nullptr, Backend,
+  return replayCachedCompilerOutputsImpl(Inputs, CAS, Diag, Opts, CDP, Backend,
                                          CacheRemarks, UseCASBackend,
                                          WriteOutputHashXAttr);
 }
 
 bool replayCachedCompilerOutputsForInput(
     ObjectStore &CAS, ObjectRef OutputRef, const InputFile &Input,
-    unsigned InputIndex, DiagnosticEngine &Diag, DiagnosticHelper &DiagHelper,
+    unsigned InputIndex, DiagnosticEngine &Diag,
     OutputBackend &OutBackend, const FrontendOptions &Opts,
     CachingDiagnosticsProcessor &CDP, bool CacheRemarks, bool UseCASBackend,
     bool WriteOutputHashXAttr) {
   llvm::SmallVector<CacheInputEntry> Inputs = {{Input, InputIndex, OutputRef}};
   return replayCachedCompilerOutputsImpl(Inputs, CAS, Diag, Opts, CDP,
-                                         &DiagHelper, OutBackend, CacheRemarks,
+                                         OutBackend, CacheRemarks,
                                          UseCASBackend, WriteOutputHashXAttr);
 }
 

lib/Tooling/libSwiftScan/SwiftCaching.cpp

@@ -987,6 +987,7 @@ static llvm::Error replayCompilation(SwiftScanReplayInstance &Instance,
 
   // Setup DiagnosticsConsumers.
   DiagnosticHelper DH = DiagnosticHelper::create(Inst, Invocation, Err);
+  DH.initDiagnosticConsumers();
 
   std::string InstanceSetupError;
   if (Inst.setupForReplay(Instance.Invocation, InstanceSetupError,
@@ -1007,7 +1008,7 @@ static llvm::Error replayCompilation(SwiftScanReplayInstance &Instance,
       makeIntrusiveRefCnt<llvm::vfs::OnDiskOutputBackend>(), Out);
 
   if (!replayCachedCompilerOutputsForInput(
-          CAS, Comp.Output, Input, Comp.InputIndex, Inst.getDiags(), DH,
+          CAS, Comp.Output, Input, Comp.InputIndex, Inst.getDiags(),
           Backend, Instance.Invocation.getFrontendOptions(), *CDP, Remarks,
           UseCASBackend,
           Instance.Invocation.getCASOptions().WriteOutputHashXAttr)) {